


Because Your Genes Look Great in Jeans

by GettingOverGreta



Category: Sherlock (TV)
Genre: Bisexual Molly Hooper, F/F, F/M, I don't know Sherlock's deal, Multi, Post-Reichenbach, Threesome - F/F/M, he's not sharing, the thinnest of plots
Language: English
Status: Completed
Published: 2017-01-08
Updated: 2017-01-08
Packaged: 2018-09-15 20:44:08
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,365
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/9256310
Author URL: https://archiveofourown.org/users/GettingOverGreta/pseuds/GettingOverGreta
Summary: Post-Reichenbach AU.  Mary enlists Sherlock's help in having a baby with her wife, Molly, in a way that will get around all sort of unpleasant bureaucratic delays. Because honestly, why the hell not.





	

**Author's Note:**

> I don't know, I was sad after The Six Thatchers, and this just sort of happened.

"My wife wants a baby." Sherlock looked up at Mary, who stood expectantly by his station in the lab. She wore a wry little smile with her dark blazer and trainers.

"And why are you informing me of this development?" Sherlock asked dryly, adding reagent to his sample.

"Because you might have noticed that we would be missing a component for that particular project, Sherlock." Mary's smile grew slightly, her eyes twinkling a bit.

"Ah. And you think I might be an appropriate donor. Have you actually asked Molly about that, because she might disagree."

"Donor? Oh, Sherlock." Mary stepped closer, suddenly much further into his personal space than he expected. His pulse increased, a slight prickle at the back of his neck took shape, and somehow he didn't think it had anything to do with being shot. "What I have in mind is so much more fun than that." She tapped him on the nose. "And involves so much less testing and paperwork. I'll text you with the details."

With that she turned and left the lab, and Sherlock paused to consider that he hadn't actually said anything in the affirmative.

But he was most definitely going to say yes.

* * *

When the day arrived (Mary sent a text saying _See you in the morning with your optimal sperm count! x_ ), Sherlock turned up per Mary's order at the flat she shared with Molly Hooper-Morstan. Mary opened the door with an enigmatic smile, and Molly emerged from the kitchen in her pajamas, looking utterly distressed.

"Sherlock, you don't have to do this. I don't know what Mary was thinking."

"I believe she was thinking that you'd like a baby, and this is the most expedient route to that goal." He nodded to Mary, who grinned at her own cleverness. :Short of kidnapping, of course, but that's generally frowned upon by society."

"Well yes, but – " Molly dropped onto the sofa and looked awkwardly at a throw pillow instead of his face. "Wouldn't you rather use a more scientific means of doing that?"

Sherlock shrugged. "The end result is the same. It's not as though you need to screen for anything. Oh, by the way –" He pulled out a list of test results from his jacket pocket. "As requested, my clean bill of health."

"Oh." Molly said, looking at the sheet of paper. She seemed to be blushing. "I mean, I've not known you to go in for – any of this."

"I've no interest in parenting or family life, Molly. Frankly, I'm surprised that Mary does, but then surprising me is an area where you both excel." Now Molly was really blushing, and Mary came over to settle next to her, putting an arm around her shoulders and taking her hand with the other.

"My darling," she kissed Molly's temple. "I know this is important to you. And I don't want you to have to wait on some list or have to pick out some anonymous idiot. I thought it should be someone we love, that we trust."

"Besides," Sherlock shrugged. "I believe I owe you a life, Molly. I didn't say it had to be my own." For a brief, awful moment, Sherlock thought Molly might cry (which was indeed consistent with Mary's tracking of her wife's cycle). Then she took a deep breath, glanced at her wife, and back to Sherlock – two people she had loved and protected from the moment she met them.

"Well then. Let's get to work, shall we?" Molly grabbed his hand and led him down the hall to their bedroom.

* * *

Sherlock had to admit that he probably should have researched what was going to happen next. He'd expected something quite perfunctory, rather like a stud horse. He simply needed to perform his function and leave, while Mary and Molly would cuddle and hope. As he watched Mary draw the curtains for privacy and light candles around the periphery of the bedroom (their bed still unmade, they'd been sleeping there a while ago – or perhaps not sleeping and thinking about their future), he realized that something a bit more complex might be expected of him.

Molly, as always, seemed to know what to do for him. She gently slipped the jacket from his shoulders, placing it neatly on a chair, and leaned up to kiss his cheek and nuzzle along his jawline. "You know she wasn't jealous, that I'd loved you so much. I think I knew she was the one because she just...understood things." Molly slid her hands over his chest and Sherlock let himself lean in to the sensation. He focused on her face upturned to his, her lips gently parted, and he wondered if it was all right to kiss her.

"Go ahead, Sherlock," Mary's voice encouraged behind him. He briefly wondered if Mary was carrying out some other desire with this tryst, but decided it didn't merit reflection. He bent down and pressed his lips to Molly's, secretly hoping that this wasn't a skill that grew rusty. She threaded her hands into his hair, making a soft little noise before sucking gently on his bottom lip. He sighed into her mouth, a sound he didn't even realize he was capable of making. Mary came up behind him, sliding her arms around his waist, and he felt the soft press of her breasts at his back.

"That looks like fun, Sherlock. Think I'd like to have a go." He stepped back to let Molly and Mary sink into each other, familiarity and comfort in their embrace. He'd seen them kiss before, but it was always casual, proper. Never like this, with the slight edge of desire that was normally private between them. Mary's hand swept up over Molly's breast, squeezing gently, making her arch softly into Mary's body.

Sherlock felt his mouth go very, very dry. He stared as Molly seemed to melt into Mary's arms, her hands roaming over Mary's arse and moving to unwind the belt of her dressing gown.

"Sherlock? Everything all right over there?" Mary smiled, unbuttoning the pearl buttons of Molly's pajamas.

"Fine. Perfectly fine." He swallowed. "You're not wearing anything under that dressing gown."

"You're just noticing that now?"

"She never does. Even in winter, just steals all the covers and tries to leech all the heat out of you." Molly stepped forward, taking Sherlock hand and carefully unbuttoning one cuff of his shirt, and then the other. "I don't recall you always wearing pajamas, either."

She made quick work of the rest of his shirt, then kissed him again. "Mary, love, I think he's nervous."

"That's adorable," Mary cooed in response, and joined Molly in pinning him against a chest of drawers. "Quite seriously though, love. We don't have to do it this way."

"We can always go with, you know, the turkey baster strategy," Molly said brightly. Sherlock glanced back and forth between Mary and Molly, both smiling sweetly. He scanned them for any sign of dishonesty, and found none. They quite genuinely meant it – they thought he was the right man for the job.

"Why?" He finally blurted.

"Because you've got good genes...that look great in jeans." Mary goosed his bum, then added, "And you will have absolutely no interest in child-rearing, but would very much enjoy the long-term observations to be made."

Molly patted his chest. "Don't worry. You can take them to the Scotland Yard museum when they're old enough. But really, if this is too much, or it's just too awkward -"

"You know, sympathy isn't much of a turn-on," Sherlock said, arching an eyebrow at Molly.

"So what is?" Mary leaned up, kissing him gently. "You can watch us a bit, if you like. Or maybe you need a bit of attention."

Molly suddenly looked slightly dismayed. "Oh god, do you need me to hit you with something?"

"What? No!"

Mary flicked her glance over both of them. "I've missed something."

"Never mind," Sherlock and Molly said at the same time, and Molly giggled. She reached up and touched his cheek, drawing his mouth down to hers again. Her kiss was lovely, and distracting. Then Mary laid a hand against his jaw and leaned in to kiss him herself. He noted as her tongue slid against his how differently her mouth tasted from Molly's. Molly let her pajama top fall away, and then kicked off the fleecy trousers.

"Isn't my wife lovely, Sherlock?" Mary said, as she unfastened his trousers. "I wouldn't have met her without you." Sherlock shivered at the feel of her hand carefully stroking him through fabric. Molly had crawled onto the bed and indeed, she looked lovely, sprawled out in their bed with her hair fanning over the pillow. Slipping off his trousers, Sherlock joined her. Molly rolled over onto her side and bit her lip, grasping his thickening cock with one strong little hand. He shivered, trying not to do (or say) anything uncouth.

"You can talk to me," Molly said sweetly. "I know you did research. You always do."

"There are no sexual positions specifically associated with conception, although it's assumed that deep penetration is helpful," he recited. Mary left her dressing gown in a heap on the floor and joined them, one lissome woman flanking him on each side. "And of course, orgasm greatly increases the chances –" Sherlock gasped as Mary, taking advantage of his distraction, took the head of his cock into her mouth. Molly nuzzled his neck and nipped playfully at his ear, tugging gently.

"What else?" she whispered, and traced the curve of his ear with her tongue.

"Mary said I had to masturbate every day to improve motility," he managed to blurt out quickly, just as Mary stopped torturing him with her mouth and straddled his hips instead.

"And did you?" Mary asked archly as she stroked up and down his torso.

"Yes," Sherlock moaned, as Mary took hold of his cock and guided him inside her. He was surprised at how slick she was, realizing that even if Molly was initially flummoxed, Mary had been thinking about how this was going to go, and getting aroused by the idea. She closed her eyes and Sherlock ran his hands over her thighs, feeling her muscles flex as she ground against him, humming with pleasure.

"That is _not_ going to get your wife pregnant," Sherlock said, trying not to sound a bit strangled because she had done something involving tightening her pelvic muscles around his cock that made him want to shout.

"Nah, but it is fun. I ride Molly's whenever I get the chance. His name's Tom." Suddenly she paused, with a very naughty expression on her face. "Have you ever tried it?"

"Um. No." He wriggled his hips, trying to get her to move again.

"Would you like to?" Mary's eyes twinkled. "I've got one that would be a good fit. I mean logistically this position probably wouldn't be the smartest thing with our heights, but –"

"I think we have other things to concentrate on at the moment, sweetheart." Molly knelt beside Mary and brushed her hand over her belly, her fingers working over Mary's clit as she looked down at Sherlock. "But maybe another time."

"Mmmm. If you don't stop doing that I might not let you have a go, Molls," Mary replied, grinding down on him in a way that made Sherlock groan.

Molly shrugged. "We've got all day. Pretty sure Sherlock could recover." She winked at him. "I'm sure we're the most important experiment he's got on today."

Mary sighed. "Yeah, but sperm count is best in the morning. Shouldn't waste that." With a slightly regretful expression she lifted herself up, letting Sherlock slip out. He pouted slightly in response, but Mary smiled and leaned over to murmur in his ear. "We've really got to attend to Molly, don't you think?" And oh, that sounded like a lovely idea.

Something Sherlock had noticed with Mary was that she seemed to comprehend with little information what he wanted in many situations, and had a gift for non-verbal direction that he found highly impressive. As a result, they were able to easily pin Molly down to the mattress in tandem, Mary teasing out all the little areas of sensation that Molly enjoyed on the sensitive skin of her throat and collarbones, while Sherlock focused on the more low-hanging fruit of her breasts. They fit beautifully into his hand, between his lips, and feeling her nipples pebble into hardness was delicious. Then Mary guided him through exactly how Molly liked to be touched as Molly panted and writhed against their hands, his fingers plunged inside her and curled into just the right spot, while Mary stroked both Molly's swollen clit and her own. Sherlock was fascinated to feel her cunt tightening, the tissues swelling around his hand.

"Now wait, Sherlock." Mary looked mischievous, and he stopped, causing Molly to let out a whine of complaint. "We have a purpose here."

Sherlock's eyes narrowed, studying the flush over Molly's skin and the pleading expression in her eyes. "Can't she have multiple orgasms?"

"Oh she absolutely can. I got her to go five times in a row once," Mary said smugly. "Practically gave myself carpal tunnel, but it was worth it. However, we have a goal here, love." She smacked Sherlock's bum lightly, and he reclaimed his fingers from Molly, letting Mary lick them clean.

"Now how do you want us, Molly?" Mary asked, and Molly looked at them thoughtfully.

"I want Sherlock from behind, while I go down on you. Does that sound alright, Sherlock?"

Sherlock blinked. "Yes, I think it's - fine. Should be fine. Not sure there's any blood in my brain right now." Mary laughed and kissed him warmly, before settling herself against the pillows along the headboard. Sherlock watched as Molly made herself comfortable between Mary's thighs. Molly gave a long, leisurely lick along the cleft of Mary's cunt, pausing to circle her clit before sweeping down again. Every motion of Molly's tongue seemed to cause some reaction, from a soft moan to a subtle contraction of an abdominal muscle.

Mary reached for his hand, squeezing it. "Better get to it, Sherlock."

Right. He had a responsibility here. He crawled behind Molly, running his hands over her back and hips, down to the lovely curve of her arse. She wiggled her bum slightly, suggesting that indeed, she was ready for him to get to it. Sherlock took hold of his cock and eased himself slowly into slick heat. He gasped, needing to utterly restrain himself to keep from simply pounding away. Molly deserved gentler treatment than that from himself. He started slowly thrusting into her, savoring how eagerly her body seemed to cling to him every time he pulled back, and the way Mary watched him keenly, her hands molding her breasts and teasing her nipples in an easy rhythm. Sherlock took a deep breath, and suddenly it all seemed like so much – Molly's heated, silken skin under his hands, the wet heat around his cock, the smell of sweat and sex, Mary's breathy moans and the wet sounds of Molly licking and sucking. The control he worked at maintaining started to fragment, his thrusts turned rougher and he quickly tried to find her clit again with a fumbling hand.

"Oh! Oh, fuck," Molly breathed, her head dropping between her arms. Mary sat up and took Molly's face in her hands. Whatever teasing or playfulness had lurked in her expression before faded away, her gaze softening into simple tenderness as she stroked Molly's hair and murmured to her that she loved her and that she so, so wanted to see her come. Molly let out a desperate groan and her hips jerked as the walls of her vagina pulsed around his cock. Relieved, Sherlock gave a few last, frantic thrusts, letting the overwhelming pleasure of finally spilling his seed inside Molly wash over him. He let himself slide out of her body and flop onto the bed as Molly wriggled around, propping her hips up on a pillow (no scientific support for that, but Sherlock supposed there was no reason to deny gravity its potential to help).

"Mary," Molly pleaded, and he blatantly stared as Mary knelt over her Molly to let her finish the job. Molly eagerly pulled Mary's hips down and nuzzled into her cunt, nose pressed into Mary's clit as she fucked her with her tongue. Mary rocked her hips, breathing harder as Molly devoured her. She looked down at Sherlock as she ran her hands over her breasts, nodding at him.

"Come along then, Sherlock," Mary said with a grin, and Sherlock dragged himself to kneel beside her. He grabbed her for a plundering kiss of her lovely mouth, and began cupping and kneading her breasts.

"Oh, a little harder darling, yes," Mary gasped, encouraging him to pinch more roughly at her nipples. She shuddered as she reached her peak, a little whine escaping her lips as she dug her fingers into Sherlock's scalp.

They settled alongside Molly, Mary curling up to her on one side while Sherlock stretched and cracked his back a bit. Curiously, Mary reached down between Molly's thighs again, and with a few swift strokes, had Molly shivering and whimpering in a second, less dramatic climax that seemed to make her settle, her whole body relaxing in release. Sherlock felt as if he was seeing something he shouldn't, a small intimacy that only a spouse, a partner would know. That moment past, Molly turned to look at him, her smile fairly glowing with fondness.

It was the first moment that he thought she could have been his Molly, if he'd been somewhat less of an idiot. Yet he had been surprised by how genuinely happy he was for her when she married Mary, how he had hoped she would forgive them both when Sherlock revealed that Mary was not just a nurse she happened to meet at Bart's and had worked for Mycroft the entire time. Even now, he was surprised to realize that Molly indeed loved him, even if she had moved on to share her life with someone who could properly reciprocate. For that matter, Molly's relationship with Mary had brought her into his circle as well – clever, resourceful Mary who seemed to understand his thinking surprisingly often.

"Earth to Sherlock," Molly said jokingly, and took his hand, entangling their fingers. "Thank you." Mary reached across her wife's chest and laid her hand over his heart.

"Yes, thank you." Mary grinned. "If it doesn't take, we can try to come up with a theme for next month. Lost marine biologist and saucy pirate wenches, perhaps?"

"You have fantasies about Darwin being ravished by pirates?"

Mary shrugged. "It's a hobby."

They broke out laughing, and Sherlock squeezed Molly's hand, letting the sensation of satisfaction sink into his bones.

* * *

Following a nap and brunch that rather swiftly devolved into a second round on the living room floor (he tried not to laugh, picturing Mary shrugging and saying they wanted to get rid of that rug anyway), Sherlock dragged himself home to Baker Street, thoroughly debauched and carrying a loaf of Mary's famous cinnamon raisin bread.

John was working on his laptop when Sherlock came in (had a successful evening last night, Sherlock noted, not successful enough to stay long afterwards) and looked up at him in surprise.

"Where've you been?" John said suspiciously.

 _Attempting to help our dear friends spawn_ , Sherlock thought, but suspected this was the sort of thing he was meant to keep under his hat.

"Around," he replied.

"You – actually got your leg over," John spluttered. Sherlock's jaw dropped slightly – he didn't expect John to figure that out quite so quickly.

"Sherlock, from this distance you reek of gorilla musk and Clair de La Lune, your hair is going in twelve directions, and only half your shirt is tucked in. Anyone could make that deduction."

"Yes, well." Sherlock shrugged. "Bound to happen eventually." With that he hurried off to get to the shower. He might have to explain himself in nine months, but he wasn't about to start yet.


End file.
